1,720,961 research outputs found
Dormancy analysis and cold hardiness of apple trees growing in warm winter conditions
No full textThe present research addressed to characterize dormancy dynamics and freezing tolerance, thus testing the efficiency of mathematical prediction models of phenology of Eva, Fuji Suprema and Galaxy apple trees. Shoots and spurs were collected between March and October 2012 and 2017, in a commercial orchard in Palmas municipality, Paraná, Brazil. The following tests were performed: Tabuenca in order to establish the final endodormancy in floral (mixed) buds; one-bud cutting test to determine dormancy dynamics in vegetative buds and; the freezing test by LT50 aiming to estimate the level of cold hardiness and its correlation with dormancy. Fifteen mathematical prediction models of phenology from the hourly temperature were tested. The phenology prediction models were inferior or as predictive as the historical average of phenology. The dynamics modeling in the form of a linear equation with breakpoint presented an attractor parameter (Bp) which offset for climate alterations and induced the release dormancy dates near the historical average. The dormancy was related to plant protection against frost damage, also the occurrence of shallow dormancy made the vegetal more susceptible to damage.Conselho Nacional do Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)O objetivo do presente trabalho foi caracterizar a dinâmica da dormência e a tolerância ao congelamento, e testar a eficiência de modelos matemáticos de predição da fenológia em macieiras Eva, Fuji Suprema e Galaxy. Brindilas e esporões foram coletados entre março e outubro de 2012 e 2017, em pomar comercial no município de Palmas-PR. Foram realizados: teste de Tabuenca para estabelecimento do final de endodormência em gemas mistas; teste de estacas com uma única gema para determinar a dinâmica da dormência em gemas vegetativas e; o teste de congelamento por LT50 visando-se estimar o nível de resistência e sua correlação com a dormência. Quinze modelos matemáticos de predição de fenologia a partir da temperatura horária foram testados. Os modelos de predição de fenologia foram inferiores ou tão preditivos quanto a média histórica da fenologia. A modelagem da dinâmica em forma de uma equação linear com ruptura apresentou um parâmetro atrator, Bp, que compensou alterações climáticas e induziu as datas de saída próximas à média histórica. A dormência relacionou-se com a proteção da planta contra danos por congelamento e a ocorrência de dormência superficial tornou a planta mais suscetível aos
danos
Análises biológicas e bioquímicas na dinâmica da dormência de macieiras em Palmas – PR
No full textO presente estudo objetivou caracterizar a dinâmica da dormência e a variação de
carboidratos e outros constituintes de ramos de macieira com baixa ('Eva') e alta
necessidade de frio ('Fuji Suprema' e 'Galaxy'), sob efeito de exposição a níveis
crescente de frio ou ao longo do período de dormência em condição de campo. Brindilas e esporões foram coletados entre março e outubro de 2012 e 2013, em pomar comercial no município de Palmas-PR. Foram realizados testes biológicos de Tabuenca (1964) e de estacas com uma única gema. Paralelamente, lenhos dos ramos das porções basais e apicais foram reservados para análise de teor de proteínas solúveis; atividade de alfa-amilase; açúcares solúveis totais (AST),
redutores (AR) e não redutores (ASNR); amido e umidade. O teste de Tabuenca (1964) pode ser aplicado em clima subtropical para estimar fim da endodormência. Entre as cultivares estudadas, 'Eva' apresenta menor exigência de frio, 'Fuji Suprema' e 'Galaxy' são equivalentes. A brotação da macieira ocorre em gradiente ao longo do ramo, com maior capacidade de brotação nas gemas laterais do ápice e em elevada exposição ao frio este gradiente deixa de ser significativo. A porção apical do lenho de ramos apresenta teores de proteínas solúveis, AST, AR, ASNR e amido e atividade de alfa-amilase maiores que na porção basal. Com o avanço na exposição ao frio ocorre aumento da atividade da alfa-amilase. A ocorrência de acúmulo de frio irregular promove a ressíntese de amido, redução da UP e atraso na brotação.The present study aimed to characterize the dormancy dynamics and the variation of
carbohydrates and other shoots constituents of apple tree with low ('Eva') and high
chilling requirement ('Fuji Suprema' and 'Galaxy'), under increasing cold levels or
over the period of dormancy in the field. Bearing shoots and spurs were collected
between March until October 2012 and 2013 in a commercial orchard in Palmas-PR. Tabuenca (1964) biological test and one bud cuttings test were performed. Simultaneously, one-year-old shoots wood, in the basal and apical portions, were reserved for soluble proteins, alpha-amylase activity, total soluble sugars, reducing and non-reducing sugars, starch and water content analysis. The Tabuenca test (1964) can be applied in subtropical climate to estimate the end endodormancy. Among the cultivars, 'Eva' has lower chilling requirement than 'Fuji Suprema' and 'Galaxy', which were equivalent. The apple tree budbreak gradient occurs along the shoot, with greater capacity for sprouting in the lateral buds of the apex. However in high exposure to cold temperature this gradient is no longer significant. The shoots apical portion present higher levels of soluble proteins, alpha-amylase activity, total soluble sugars, reducing and non-reducing sugars and starch than the basal portion. With the advancement of cold exposure the alpha-amylase activity increased. The
occurrence of irregular chilling accumulation promotes starch resynthesis, water content decrease and sprouting delay
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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